... The octakis(trimethylsiloxy)calix[4]resorcinarenes, 3 and 4, were synthesized by reaction of 1 and its tetrabromo derivative 2 with hexamethyldisilazane, and were found to exhibit dynamic behaviour in solution. Temperature-dependent NMR investigations confirmed the presence of at least two conformational isomers of 3 in solution. The conformation of 3 in the solid state was determined by an X-ray ...

... The reaction of bis(t-butylamino)dimethylsilane with titanium tetrachloride in dichloromethane solution leads to a mixture of compounds from which the imido complex (H₃NCMe₃)₂[TiCl₃(N-CMe₃)]₂ (1) and by extraction of the residue with acetonitrile the imido complex [TiCl₂(N-CMe₃)(H₂N-CMe₃)(CH₃CN)]₂ (2) can be isolated. 1 reacts with acetonitrile to give the ketimido complex [TiCl₃{NC(Me)N(H)CMe₃}(C ...

... The crystal structure of the binuclear Cu(II) complex [Cu(mef)₂DMSO]₂ (mef = deprotonated N-2,3-dimethylphenyl-anthranilic acid; DMSO = dimethylsulfoxide) has been determined by single-crystal X-ray diffractometry. It crystallizes in the triclinic space group P1̄ with Z = 1. IR and electronic spectra of the compound are also discussed briefly. ...

... Tricarbonyl(η⁶-cyclooctatetraene)metal(0) complexes of the group 6 elements were prepared by using the procedures described in the literature with some minor modifications and identi­fied by IR and NMR spectroscopy. Their electrochemical behavior was studied by using cyclic voltammetry in dichloromethane solution containing 0.1 M tetrabutylammonium tetrafiuorob-orate as supporting electrolyte. The ...

... The low temperature preparation of the bistrimethylsilylester of carbonic acid is reported. The hydrolysable and thermolabile (Me₃SiO)₂CO has been characterized by vibrational and NMR spectroscopic methods. Under inert conditions the (Me₃SiO)₂CO is stable at 233 K for several weeks. ...

... By reaction of [B₆H₆]²⁻with (SCN)₂ in dichloromethane at -80 C° the thiocyanatohexaborate anion is formed and can be isolated by ion exchange chromatography on diethylaminoethyl (DEAE) cellulose. The X-ray structure determination of Cs₂[B₆H₅(SCN)] (orthorhombic, space group Pbca with a = 9.506(5), b = 10.644(5), c = 21.857(5) Å, Z = 8) reveals that the SCN substituent is bonded via the S atom with ...

... The stability constants of the 1:1 complexes formed between Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ or Cd²⁺ (= M²⁺) and 5,6-dichloro-l-(β-ᴅ-ribofuranosyl)benzim idazole (DRB) were determined by potentiom etric pH titrations in aqueous solution (25 °C; I = 0.5м, NaNO₃). The acidity constant of H(DRB)⁺, the proton being at N3, was measured by the same method and the result was confirmed ...

... The preparation, crystal structures and optical absorption spectra of [H₃N(CH₂)₆NH₃]BiX₅ (X= I, Cl) and [H₃N(CH₂)₆NH₃]SbX₅ (X =I, Br) are reported. The anions of the compounds consist of MX₆-octahedra (M =Bi, Sb) sharing cisvertices in one-dimensional zig-zag chains. Because of their one-dimensional character, a blue shift of the excitonic absorption bands, in com parison to those of higher dim en ...

... Facets of molecular dynamics in organic compounds such as coupled rotations of adjacent substituents are advantageously discussed based on structural data. Within this context, crystal structures of spatially overcrowded ortho-disubstituted benzene derivatives with chloromethyl or methylamino groups are presented together with semiempirical enthalpy hypersurfaces for the substituent rotation. Both ...

... ortho-Benzene derivatives with adjacent bulky propeller substituents are well-suited model compounds to investigate their potentially coupled rotations. To approach the molecular dynamics of 1,2-bis(trimethylsilyl)benzene, a liquid at room temperature and containing heteroelement substituents, an advantageous starting point are the crystal structures of the stereochemically correspondent benzene-1 ...

... The 2,3-dihydro-1,3,4,5-tetraalkylimidazol-2-ylidenes 3 (R = Me, iso-Pr) react immediately with pentafluoropyridine to form the 2-tetrafluoropyridylimidazolium salts 4 in good yields. In contrast with the tetramethyl derivative 4a, alkyl fluoride is eliminated from the isopropyl salt 4b to give 1 -isopropyl-4,5-dimethyl-2-tetrafluoropyridylimidazole, which dimerises via hydrogen bridges in the sol ...